The present invention relates to coal gasification, and more particularly, the invention relates to an efficient process for producing ultra clean liquid fuels from coal waste and mine tailings.
Abandoned mine waste is abundant in most coal mining regions. As one example of such a region, coal mining companies in the first half of the 20th century hauled the purest anthracite coal from northeastern Pennsylvania and left behind vast quantities of waste coal consisting of small hunks of anthracite mixed with other rocks. The waste coal remains in vast, messy, acid-leaching piles that blight the landscape and provide a nasty environmental legacy from the past mining operations. It is estimated that between 82 and 140 million cubic yards of coal mining waste material is present in just the forty largest coal mining waste piles in northeastern Pennsylvania's anthracite region.
Accordingly, there is need for an efficient means for converting the aforementioned coal waste into a clean synthetic gas that can be used, for instance, in power plants to generate electricity and in liquid fuel production plants to produce ultra clean liquid fuels and other value-added products. The productive use of such material will result in the cleaning up of millions of tons of waste coal piles and will enable the reclamation of vast areas of abandoned mine land. The ultra clean liquid fuels can be provided as superior transportation fuels that are virtually free of sulfur and that are low in particulates and aromatics. Such fuel production will also reduce the region's dependency on importing foreign oil.